In the processing of semiconductor materials for the ultimate manufacture of integrated circuits and the like, a number of steps must be performed on silicon wafers. Typically, such processing of the silicon wafer includes scrubbing the wafer to clean it and then baking it, and/or coating the wafer and then baking it, and/or developing the wafer and then baking it. In addition, such processes are typically performed by transferring the wafer to a plurality of different work stations or machines, each of which have the capacity for performing only one of these functions. For example, the wafers may be cleaned in a scrubber and then transferred to a separate apparatus for baking. Then, the wafers may again be transferred to another apparatus for coating with dopant and then returned to the baking apparatus. Similarly, the wafers may be transferred to a developing location, and then returned to the baking apparatus.
As will be understood, such processing which requires the transferring of the wafers to a plurality of different work stations is time consuming, costly, and inefficient. It would therefore be highly desirable to provide an arrangement wherein all of the necessary processes to be performed on the wafer can be performed on the wafer while it is positioned at a single location or station, which would avoid all of the transferring oprations between each different process which are now required. In addition, it would also avoid the need for the costly apparatus for transferring the workpieces between the various work stations or machines.
With respect to the baking operation presently being performed to bake the silicon wafers, such arrangements typically include a conveyor which moves the wafer through an oven so that the wafer, which may or may not be microwave heated, is baked as it moves through the oven. Such an arrangement requires a relatively large apparatus and complex conveyor arrangement which allows the wafer to be baked as it traverses the oven. Accordingly, it would also be highly desirable to avoid the need for such a large and complex apparatus to bake the silicon wafers.
Broadly, it is an object of the present invention to provide an improved arrangement which overcomes one or more of the aforesaid problems. Specifically, it is within the contemplation of the present invention to provide an arrangement wherein all of the processing functions to be performed on a silicon wafer, including scrubbing, coating, developing, and/or baking, can be performed at a single work station and thereby avoid the need for transferring the silicon wafer between a plurality of different work stations in order to complete its processing.
It is a further object of the present invention to provide an improved processing apparatus for silicon wafers which processes such wafers in a highly-efficient manner by reducing the time it takes to perform such operations and by substantially reducing the complexity of the apparatus required.
It is a still further object of the present invention to provide an improved arrangement for baking of silicon wafers wherein the wafers are maintained at a single station while they are being baked and otherwise processed.